Pulse transmission transceiver architecture for low power communications

• US 20020146080A1
• Filed: 02/25/2002
• Published: 10/10/2002
• Est. Priority Date: 09/23/1999
• Status: Active Grant

• Current Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Inventors: Smith, Stephen F., Dress, William B. Jr.
• Granted Patent: US 6,621,878 B2
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 1/7172 Pulse shape in general H04L25/03834
• CPC Class Codes: H04B 1/7174 Pulse generation in general H04L25/03834
• CPC Class Codes: H04B 1/719 Interference-related aspects
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 25/49 using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems spectral shaping H04L25/03828

Abstract

Systems and methods for pulse-transmission low-power communication modes are disclosed. A method of pulse transmission communications includes: generating a modulated pulse signal waveform; transforming said modulated pulse signal waveform into at least one higher-order derivative waveform; and transmitting said at least one higher-order derivative waveform as an emitted pulse. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

Claims

1. A method of pulse transmission communications, comprising:

generating a pulse-signal waveform;

transforming said pulse-signal waveform into at least one higher-order derivative waveform; and

transmitting said at least one higher-order derivative waveform as an emitted pulse.

2. The method of claim 1, wherein said at least one higher-order derivative waveform is modulated by an on/off information signal.

3. The method of claim 2, further comprising modulating said at least one higher-order derivative waveform with an analog technique selected from the group consisting of amplitude modulation, frequency modulation, and phase modulation.

4. The method of claim 2, further comprising modulating said at least one higher-order derivative waveform with a digital binary technique selected from the group consisting of phase-shift keying, binary phase-shift keying, quadrature phase-shift keying, offset quadrature phase-shift keying, frequency-shift keying, minimum-shift keying, amplitude shift keying, and on-off keying.

5. The method of claim 2, further comprising modulating said at least one higher-order derivative waveform with a multi-state technique selected from the group consisting of multi-state data frequency-shift keying, multi-state data phase-shift keying, multi-state data quadrature amplitude modulation, ternary digital modulation, and n-state digital modulation.

6. The method of claim 1, wherein transforming said pulse-signal waveform into said at least one higher-order derivative waveform includes shaping a frequency spectrum of said emitted pulse to reduce lower frequency emissions.

7. The method of claim 1, wherein transforming said pulse-signal waveform into said at least one higher-order derivative waveform includes orthogonally encoding a single bit signal into said emitted pulse.

8. The method of claim 1, wherein said at least one higher-order derivative waveform is modulated by a multiple-bit signal.

9. The method of claim 7, wherein orthogonally encoding a multiple-bit signal into said emitted pulse includes adding a plurality of higher-order derivative waveforms that are a function of said pulse-signal waveform.

10. The method of claim 1, wherein said pulse-signal waveform represents a Gaussian function.

11. The method of claim 1, wherein said pulse-signal waveform is a time-domain function exp(−

x²ⁿ/2a), where x is the function in each domain, a is a constant, and n is an integer that represents an order.

12. The method of claim 1, wherein transforming said pulse-signal into said at least one higher-order derivative includes transforming said pulse signal with active circuitry.

13. The method of claim 1, wherein generating said pulse-signal waveform includes generating said pulse signal waveform from a stored digital version.

14. The method of claim 1, further comprising repeating the step of generating said pulse-signal waveform to achieve orthogonal time hopping.

15. The method of claim 1, further comprising repeating at least one step selected from the group consisting of generating said pulse-signal waveform and transforming said pulse-signal waveform into said at least one higher-order derivative waveform, to achieve orthogonal frequency hopping.

16. The method of claim 1, further comprising repeating at least one step selected from the group consisting of generating said pulse-signal waveform and transforming said pulse-signal waveform into said at least one higher-order derivative waveform, to achieve combined orthogonal frequency-time hopping.

18. The electromagnetic waveform of claim 17, wherein a frequency spectrum of said emitted pulse is shaped to reduce at least one member selected from the group consisting of lower frequency emissions and higher frequency emissions.

19. The electromagnetic waveform of claim 17, wherein said emitted pulse orthogonally encodes a multiple-bit signal.

20. The electromagnetic waveform of claim 19, wherein said multiple-bit signal is encoded into said emitted pulse by adding a plurality of higher-order derivative waveforms that are a function of said pulse-signal waveform.

21. The electromagnetic waveform of claim 17, wherein said pulse-signal waveform is a Gaussian function.

22. The electromagnetic waveform of claim 17, wherein said pulse-signal waveform represents a time-domain function exp(−

x²n/a), where x is the function in each domain, a is a constant, and n is an integer that represents an order.

23. An orthogonal time-hopping electromagnetic waveform that includes the electromagnetic waveform of claim 17.

24. An orthogonal frequency-hopping electromagnetic waveform that includes the electromagnetic waveform of claim 17.

25. A combined orthogonal frequency-time hopping electromagnetic waveform that includes the electromagnetic waveform of claim 17.

27. The pulse transmitter of claim 26, further comprising a programmable delay circuit coupled to said trigger signal generator.

28. The pulse transmitter of claim 26, further comprising at least one information modulator circuit coupled to said at least one higher-order pulse generator wherein said at least one information modulator circuit provides at least one function selected from the group consisting of amplitude modulation, frequency modulation, phase modulation, digital binary modulation, phase-shift keying, binary phase-shift keying, quadrature phase-shift keying, offset quadrature phase-shift keying, frequency-shift keying, minimum-shift keying, amplitude shift keying, on-off keying, multi-state data frequency-shift keying, multi-state data phase-shift keying, multi-state data quadrature amplitude modulation, ternary digital modulation, and n-state digital modulation.

29. The pulse transmitter of claim 26, further comprising at least one summation circuit coupled to said at least one higher-order derivative pulse generator.

30. The pulse transmitter of claim 29, wherein said at least one summation circuit includes at least one member selected from the group consisting of a passive combiner, an active summing circuit, and a digital combining circuit.

31. The pulse transmitter of claim 26, further comprising a power amplifier coupled to said at least one higher-order derivative pulse generator.

32. The pulse transmitter of claim 26, further comprising data encoder circuitry coupled to said at least one higher-order derivative pulse generator.

33. The pulse transmitter of claim 28, further comprising data encoder circuitry coupled to said at least one information modulator circuit.

34. The pulse transmitter of claim 28, further comprising a spread-spectrum data modulator coupled to said at least one information modulator circuit.

35. The pulse transmitter of claim 34, wherein said spread-spectrum data modulator provides at least one spread-spectrum mode selected from the group consisting of direct sequence, frequency hopping, and time-hopping.

36. The pulse transmitter of claim 26, including a demultiplexer coupled to said at least one higher-order derivative pulse generator.

37. The pulse transmitter of claim 28, further comprising a demultiplexer coupled to said at least one information modulator circuit.

38. The pulse transmitter of claim 29, further comprising a synchronization-pulse generator coupled to said at least one summation circuit.

39. The pulse transmitter of claim 26, further comprising a matching network connected to said output-interface device.

40. The pulse transmitter of claim 26, wherein said output-interface includes an antenna.

41. The pulse transmission transmitter of claim 27, wherein said programmable delay circuit includes a programmable-delay monostable multivibrator circuit.

42. The pulse transmission transmitter of claim 26, wherein said at least one higher-order derivative pulse generator includes a filter.

43. The pulse transmission transmitter of claim 42 where said filter includes a Gaussian filter.

44. A one-chip integrated circuit including the pulse transmission transmitter of claim 26.

46. The pulse transmission receiver of claim 45, further comprising at least one received pulse detection circuit coupled to said at least one higher-order derivative pulse generator.

47. The pulse transmission receiver of claim 46, wherein said at least one received pulse detection circuit includes a synchronous pulse correlator.

48. The pulse transmission receiver of claim 47, wherein said at least one higher-order derivative pulse generator includes a data demodulator.

49. The pulse transmission receiver of claim 48, wherein said data demodulator provides at least one function selected from the group consisting of amplitude demodulation, frequency demodulation, phase demodulation, digital binary demodulation, phase-shift keying, binary phase-shift keying, quadrature phase-shift keying, offset quadrature phase-shift keying, frequency-shift keying, minimum-shift keying, amplitude shift keying, on-off keying, multi-state data frequency-shift keying, multi-state data phase-shift keying, multi-state data quadrature amplitude demodulation, ternary digital demodulation, and n-state digital demodulation.

50. The pulse transmission receiver of claim 45, further comprising a programmable delay circuit connected between said trigger signal generator and said at least one higher-order derivative pulse generator.

51. The pulse transmission receiver of claim 45, including a multiplexer coupled to said at least one higher-order derivative pulse generator.

52. The pulse transmission receiver of claim 51, further comprising a data despreader coupled to said multiplexer.

53. The pulse transmission receiver of claim 52, further comprising a connection between said data despreader and said synchronization circuit adapted to provide automatic frequency/synchronization control.

54. The pulse transmission receiver of claim 45, further comprising a matching network connected to said front-end amplification/processing circuit;

.

55. The pulse transmission receiver of claim 54, further comprising an antenna coupled to said matching network.

56. The pulse transmission receiver of claim 45, wherein said at least one higher-order derivative pulse generator includes a filter.

57. The pulse transmission receiver of claim 56 where said filter includes a Gaussian filter.

58. A one-chip integrated circuit including the pulse transmission receiver of claim 45.

60. The method of claim 59, wherein transforming said pulse position modulated signal waveform into said at least one higher-order derivative waveform includes shaping a frequency spectrum of said emitted pulse to reduce lower frequency emissions.

61. The method of claim 59, wherein transforming said pulse position modulated signal waveform into said at least one higher-order derivative waveform includes orthogonally encoding or modulating a single bit signal into said emitted pulse.

62. The method of claim 61, wherein orthogonally encoding a multiple-bit signal into said emitted pulse includes adding a plurality of higher-order derivative waveforms that are a function of said pulse-signal waveform.

63. The method of claim 59, wherein said pulse position modulated signal waveform represents a Gaussian function.

64. The method of claim 59, wherein said pulse-signal waveform is a time-domain function exp(−

x²ⁿ/a), where x is the function in each domain, a is a constant, and n is an integer that represents an order.

65. The method of claim 59, wherein transforming said pulse position modulated signal into at least one higher-order derivative includes transforming said pulse position modulated signal with active circuitry.

66. The method of claim 59, wherein generating said pulse position modulated signal waveform includes generating said pulse position modulated signal from a stored digital version.

67. The method of claim 59, further comprising repeating the step of generating said pulse position modulated signal waveform to achieve orthogonal time hopping.

68. The method of claim 59, further comprising repeating at least one step selected from the group consisting of generating said pulse position modulated signal waveform and transforming said pulse position modulated signal waveform into said at least one higher-order derivative waveform to achieve orthogonal frequency hopping.

70. The electromagnetic waveform of claim 69, wherein a frequency spectrum of said emitted pulse is shaped to reduce lower frequency emissions.

71. The electromagnetic waveform of claim 69, wherein said emitted pulse orthogonally encodes a multiple bit signal.

72. The electromagnetic waveform of claim 71, wherein said multiple bit signal is encoded into said emitted pulse by adding a plurality of higher-order derivative waveforms that are a function of said modulated pulse-signal waveform.

73. The electromagnetic waveform of claim 69, wherein said pulse position modulated signal waveform represents a Gaussian or other appropriate mathematical function.

74. An orthogonal time-hopping electromagnetic waveform that includes the electromagnetic waveform of claim 69.

75. An orthogonal frequency-hopping electromagnetic waveform that includes the electromagnetic waveform of claim 69.

17. An electromagnetic waveform, comprising:

an emitted pulse that is produced from at least one higher-order derivative waveform of a pulse-signal waveform.

26. A pulse transmission transmitter, comprising:

a clock;

a trigger signal generator coupled to said clock;

at least one higher-order derivative pulse generator coupled to said trigger signal generator;

a selector circuit coupled to said at least one higher-order derivative pulse generator; and

an output-interface device coupled to said at least one higher-order derivative pulse generator.

45. A pulse transmission receiver, comprising:

a front-end amplification/processing circuit;

a synchronization circuit coupled to said front-end amplification/processing circuit;

a clock coupled to said synchronization circuit;

a trigger signal generator coupled to said clock; and

at least one higher-order derivative pulse generator coupled to said trigger signal generator.

59. A method of pulse transmission communications, comprising:

generating a pulse position modulated signal waveform;

transforming said pulse position modulated signal waveform into at least one higher-order derivative waveform; and

transmitting said at least one higher-order derivative waveform as an emitted pulse.

69. An electromagnetic waveform, comprising:

an emitted pulse that is produced from at least one higher-order derivative waveform of a pulse position modulated signal waveform.

76. A pulse transmission transmitter, comprising:

a clock;

a pseudorandom polynomial generator coupled to said clock, said pseudorandom polynomial generator having a polynomial load input;

an exclusive-OR gate coupled to said pseudorandom polynomial generator, said exclusive-OR gate having a serial data input;

a programmable delay circuit coupled to both said clock and said exclusive-OR gate;

a pulse generator coupled to said programmable delay circuit;

a filter coupled to said pulse generator; and

an antenna coupled to said matching network.

77. The pulse transmission transmitter of claim 76, wherein said programmable delay circuit includes a programmable-delay monostable multivibrator circuit.

78. The pulse transmission transmitted or claim 76, herein said filter includes a Gaussian filter.

79. The pulse transmitter of claim 76, wherein said clock, said pseudorandom polynomial generator, said exclusive-OR gate, said programmable delay circuit, said pulse generator and said filter all compose a one-chip integrated circuit.

80. A pulse transmission receiver, comprising:

a correlator;

a demodulation decoder coupled to said correlator;

a clock coupled to said demodulation decoder; and

a pseudorandom polynomial generator coupled to both said correlator and said clock.

81. The pulse transmission receiver of claim 80, further comprising a gate coupled to said correlator.

82. The pulse transmission receiver of claim 81, further comprising a trigger coupled to said correlator.

83. The pulse transmission receiver of claim 82, further comprising an integral automatic gain-control loop coupled to both said gate and said trigger.